Influence of the photon - neutrino processes on magnetar cooling

The photon-neutrino processes $\gamma e^{\pm} \to e^{\pm} \nu \bar \nu$, $\gamma \to \nu \bar \nu$ and $\gamma \gamma \to \nu \bar \nu$ are investigated in the presence of a strongly magnetized and dense electron-positron plasma. The amplitudes of the reactions $\gamma e^{\pm} \to e^{\pm} \nu \bar \nu$ and $\gamma \gamma \to \nu \bar \nu$ are obtained. In the case of a cold degenerate plasma contributions of the considering processes to neutrino emissivity are calculated. It is shown that contribution of the process $\gamma \gamma \to \nu \bar \nu$ to neutrino emissivity is supressed in comparision with the contributions of the processes $\gamma e^{\pm} \to e^{\pm} \nu \bar \nu$ and $\gamma \to \nu \bar \nu$. The constraint on the magnetic field strength in the magnetar outer crust is obtained.Comment: 8 pages, LaTeX, 2 PS figures, based on the talk presented by D.A. Rumyantsev at the XV International Seminar Quarks'2008, Sergiev Posad, Moscow Region, May 23-29, 2008, to appear in the Proceeding

Results of a search for 2β\beta-decay of 136^{136}Xe with high-pressure copper proportional counters in Baksan Neutrino Observatory

The experiment for the 2$\beta$-decay of $^{136}$Xe search with two high-pressure copper proportional counters has been held in Baksan neutrino observatory. The search for the process is based on comparison of spectra measured with natural and enriched xenon. No evidence has been found for 2$\beta$(2$\nu$)- and 2$\beta$(0$\nu$)-decay. The decay half lifetime limit based on data measured during 8000 h is T$_{1/2}$$\geq8.5\cdot10^{21}$yr for 2$\nu$-mode and T$_{1/2}$$\geq3.1\cdot10^{23}$yr for 0$\nu$-mode (90%C.L.).Comment: 9 pages, 8 figures; talk at the NANP'05 Conference; submitted to Phys. At. Nuc

One-loop radiative corrections to photon-pair production in polarized positron-electron annihilation

A theoretical description of photon-pair production in polarized positron-electron annihilation is presented. Complete one-loop electroweak radiative corrections are calculated taking into account the exact dependence on the electron mass. Analytical results are derived with the help of the SANC~system. The relevant contributions to the cross section are calculated analytically using the helicity amplitude approach. The cases of unpolarized and longitudinally polarized fermions in the initial state are investigated. Calculations are realized in the Monte Carlo integrator MCSANCee and generator ReneSANCe which allow one the implementation of any experimental cuts used in the analysis of $e^+e^-$ annihilation data of both low and high energies.Comment: 17 pages, 6 tables, 3 figure

Forming and development of law-making principles system and its meaning for legal enforcement of suitable legal regulation model

There is a law-making principles system worked out in the paper. It plays the great role in creation or choice of legal regulation model. When elaborating the latter, the deep interaction between law-making and law principles takes place. The deeper interaction is put by a legislator into model background the better public regulation is carried ou

DDAO Controlled Synthesis of Organo-Modified Silica Nanoparticles with Encapsulated Fluorescent Boron Dipyrrins and Study of Their Uptake by Cancerous Cells

The design of cargo carriers with high biocompatibility, unique morphological characteristics, and capability of strong bonding of fluorescent dye is highly important for the development of a platform for smart imaging and diagnostics. In this paper, BODIPY-doped silica nanoparticles were prepared through a "one-pot" soft-template method using a sol-gel process. Several sol-gel precursors have been used in sol-gel synthesis in the presence of soft-template to obtain the silica-based materials with the most appropriate morphological features for the immobilization of BODIPY molecules. Obtained silica particles have been shown to be non-cytotoxic and can be effectively internalized into the cervical cancer cell line (HeLa). The described method of synthesis allows us to obtain silica-based carriers with an immobilized fluorescent dye that provide the possibility for real-time imaging and detection of these carriers

Transition from Fireball to Poynting-flux-dominated Outflow in Three-Episode GRB 160625B

The ejecta composition is an open question in gamma-ray bursts (GRB) physics. Some GRBs possess a quasi-thermal spectral component in the time-resolved spectral analysis, suggesting a hot fireball origin. Others show a featureless non-thermal spectrum known as the "Band" function, consistent with a synchrotron radiation origin and suggesting that the jet is Poynting-flux-dominated at the central engine and likely in the emission region as well. There are also bursts showing a sub-dominant thermal component and a dominant synchrotron component suggesting a likely hybrid jet composition. Here we report an extraordinarily bright GRB 160625B, simultaneously observed in gamma-rays and optical wavelengths, whose prompt emission consists of three isolated episodes separated by long quiescent intervals, with the durations of each "sub-burst" being $\sim$ 0.8 s, 35 s, and 212 s, respectively. Its high brightness (with isotropic peak luminosity L$_{\rm p, iso}\sim 4\times 10^{53}$ erg/s) allows us to conduct detailed time-resolved spectral analysis in each episode, from precursor to main burst and to extended emission. The spectral properties of the first two sub-bursts are distinctly different, allowing us to observe the transition from thermal to non-thermal radiation between well-separated emission episodes within a single GRB. Such a transition is a clear indication of the change of jet composition from a fireball to a Poynting-flux-dominated jet.Comment: Revised version reflecting the referees' comments. 27 pages, 11 figures, 5 tables. The final edited version will appear in Nature Astronom

Elemental analysis of teeth roots treated with nanoimpregnation technologies

The aim of the study was to investigate the new method of impregnation of the root canal system with an antibacterial drug based on calcium hydroxocuprate and copper nanoparticles hydrosol.Целью исследования является обоснование нового метода импрегнации системы корневых каналов зубов антибактериальным препаратом на основе гидроксокупрата кальция, гидрозоля наночастиц меди и её оксидов

The central engine of GRB 130831A and the energy breakdown of a relativistic explosion

Gamma-ray bursts (GRBs) are the most luminous explosions in the universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these events. We present optical and X-ray observations of GRB 130831A obtained by Swift, Chandra, Skynet, RATIR, Maidanak, ISON, NOT, LT and GTC. This burst shows a steep drop in the X-ray light-curve at $\simeq 10^5$ s after the trigger, with a power-law decay index of $\alpha \sim 6$. Such a rare behaviour cannot be explained by the standard forward shock (FS) model and indicates that the emission, up to the fast decay at $10^5$ s, must be of "internal origin", produced by a dissipation process within an ultrarelativistic outflow. We propose that the source of such an outflow, which must produce the X-ray flux for $\simeq 1$ day in the cosmological rest frame, is a newly born magnetar or black hole. After the drop, the faint X-ray afterglow continues with a much shallower decay. The optical emission, on the other hand, shows no break across the X-ray steep decrease, and the late-time decays of both the X-ray and optical are consistent. Using both the X-ray and optical data, we show that the emission after $\simeq 10^5$ s can be explained well by the FS model. We model our data to derive the kinetic energy of the ejecta and thus measure the efficiency of the central engine of a GRB with emission of internal origin visible for a long time. Furthermore, we break down the energy budget of this GRB into the prompt emission, the late internal dissipation, the kinetic energy of the relativistic ejecta, and compare it with the energy of the associated supernova, SN 2013fu.Comment: Accepted for publication by MNRAS. 21 pages, 3 figures, 8 tables. Extra table with magnitudes in the sourc